program xmz;
var
f1,f2:text;
a,n,b,ss,t1,t2:Longint;
f:array[1..100,1..100]of longint;
s:array[1..100]of longint;
min:int64;
procedure floyd;
var k,i,j:longint;
 begin
  for k:=1 to n do
  for i:=1 to n do
   for j:=1 to n do
    if f[i,j]>f[i,k]+f[k,j] then
    f[i,j]:=f[i,k]+f[k,j];
 end;
begin
assign(f1,'hospital.in');assign(f2,'hospital.out');
reset(f1);rewrite(f2);
read(f1,n);
for a:=1 to n do for b:=1 to n do f[a,b]:=9999999;
for a:=1 to n do
 begin
  read(f1,s[a],t1,t2);
  if t1<>0 then begin f[t1,a]:=1;f[a,t1]:=1;end;
  if t2<>0 then begin f[a,t2]:=1;f[t2,a]:=1;end;
 end;
floyd;

min:=9999999999;
for a:=1 to n do
 begin
  for b:=1 to n do if a<>b then ss:=f[a,b]*s[b]+ss;
  if ss<min then min:=ss;
  ss:=0;
 end;
if min=9999999999 then write(f2,0) else write(f2,min);
close(f1);close(f2);
end.